Compound

Ar

R¹

R²

M.p. (lit. m. p.)/[˚C]

H₂O^a

Solvent-free^b

Ref.

Yield [%]^c

Yield [%]^c

3a

C₆H₅

H

H

287-289 (288-290)

92

87

[36]

3b

2-Cl-C₆H₄

H

H

231-233 (233-234)

86

87

[41]

3c

4-Cl-C₆H₄

H

H

291-293 (287-289)

89

88

[37]

3d

3-NO₂-C₆H₄

H

H

204-207 (205)

88

87

[38]

3e

4-NO₂-C₆H₄

H

H

325-327 (328)

90

91

[40]

3f

3-MeO-C₆H₄

H

H

202-205 (201-204)

86

83

[41]

3g

4-MeO-C₆H₄

H

H

223-226 (225)

93

90

[38]

3h

4-Me-C₆H₄

H

H

275-276 (278)

92

90

[38]

3i

4-Br-C₆H₄

H

H

299-300 (298)

85

87

[40]

3j

2-C₄H₄S

H

H

330-333 (330)

90

88

[40]

3k

C₆H₅

Me

H

240-242 (241-242)

93

91

[36]

3l

2-Cl-C₆H₄

Me

H

104-106 (106-108)

87

88

[36]

3m

4-Cl-C₆H₄

Me

H

225-227 (224)

90

89

[42]

3n

C₆H₅

Me

Me

251-252 (244-247)

85

87

[39]

3o

2-C₄H₄S

Me

Me

240-242

93

91

[43]

3p

3-MeO-C₆H₄

Me

Me

240-243

93

90

[43]